|Centuries:||7th century – 8th century – 9th century|
|Decades:||760s 770s 780s – 790s – 800s 810s 820s|
|Years:||787 788 789 – 790 – 791 792 793|
|790 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1543|
|Chinese calendar||己巳年 (Earth Snake)
3486 or 3426
— to —
庚午年 (Metal Horse)
3487 or 3427
|- Vikram Samvat||846–847|
|- Shaka Samvat||712–713|
|- Kali Yuga||3891–3892|
|Japanese calendar||Enryaku 9
|Minguo calendar||1122 before ROC
|Seleucid era||1101/1102 AG|
|Thai solar calendar||1332–1333|
|Wikimedia Commons has media related to 790.|
Year 790 (DCCXC) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. The denomination 790 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
- September – The Armeniac Theme located in northeastern Asia Minor (modern Turkey) revolt against empress Irene and declare the 19-year-old Constantine VI sole ruler of the Byzantine Empire. Other themes follow their example and imprison their strategoi. Constantine sends his iconoclast general Michael Lachanodrakon to ensure that the Armeniacs—his closest supporters–take an oath. Irene is confined and imprisoned in her palace at Constantinople, all her eunuchs are exiled.
- Alcuin, Anglo-Saxon missionary, returns after 8 year of absence to England. During his stay at the Carolingian court of king Charlemagne in Aachen, he educates his sons Charles, Pepin and Louis. Alcuin revises the church liturgy and the Bible, and is responsible for an intellectual movement within the Frankish Kingdom.
- King Æthelred I returns to Northumbria and is restored to the throne after living in exile for 11 years. His rival Osred II is deposed, forcibly tonsured, and exiled to the Isle of Man. Æthelred then faces a rebellion by another rival, named Eardwulf. The latter is captured and hanged outside the gates to Ripon Abbey. The body is taken into the abbey where Eardwulf recovers and escapes to exile.
- King Offa of Mercia takes control of East Anglia. King Æthelberht II mints his own coins in defiance of his overlord (approximate date).
- Cambodia begins to break away from the Sumatra-based kingdom Srivijaya as a 20-year-old Cambodian prince who claims descent from the rulers of Funan is consecrated in eastern Cambodia with the title Jayavarman II. In the next 10 years he will extend his powers north into the Mekong Valley (modern Vietnam).
- Irish monks (known as the Papar), possibly members of a Hiberno-Scottish mission, reach Iceland in hide-covered coracles and begin settlements (approximate date).
- Angilbert, Frankish diplomat (primicerius palatii) of king Charlemagne, is made abbot of Saint-Riquier (Northern France).
- Fātimah bint Mūsā, Muslim saint (d. 816)
- Leo IV, pope of the Catholic Church (d. 855)
- Li He, Chinese poet (d. 816)
- Lu Tong, Chinese poet (d. 835)
- Ramiro I, king of Asturias (approximate date)